The listed 3S 130C 5000-mAh Turnigy Nanotech cells seem to be working fine for several builders. However, some potential customers have converns about using LiPo, so I am investigating what an alternative power supply might look like. I am currently thinking a hybrid pack that uses four high-current...

Thanks for posting EbikeAus. Lately I have been thinking about putting together a hybrid system. Originally, I thought I would get four 20-Ah high-current flat foil packs from EIG ($220). Now I am leaning towards four large LiFePO4 15-Ah cylindrical cells, and a capacitor bank to help with burst amp...

I wouldn't charge LiFePO4 up to 4.2V per cell, but...I have read that doing so will not cause the electrolyte to off-gas. This is touted as one of the reasons LiFePO4 is considered to be very safe, and less likely to catch fire. I have recently become interested in 4S LiFePO4 as a 12V SLA replacemen...

When my submarine pulled into Australia (Perth, a lovely city with fun people), there were protesters at the Navy base gate with anti-nuke signs. We braced ourselves for trouble and planned to take quite a bit of abuse when passing through the gate (without causing an international incident). The pr...

I've wondered this for years, and someone finally clued me in to the fact that nuke missiles have to have their warheads refreshed every so often, and light water uranium reactors can produce fresh plutonium as a byproduct. I don't know how much of an influence this on policy decisions, but..I'd lik...

The main reason the Powerwall guys use individual fuses on the cells (even though it's a fixed non-mobile installation) is because it's popular to build with used cells that are typically $1 each. Sometimes they overheat under normal use...

I'm not a fan of soldering onto cell ends, especially the negative electrode, but I have to say I would definitely not use the technique shown. He says to get a good soldering iron, and then he shows a 40W unit with a fairly small tip. Then he holds the hot tip onto the negative electrode as an exam...

I've read that crimps can withstand a level of heat that would re-melt a soldered connection. However, my personal opinion is that no joint should ever get so hot that any solder that is present would be damaged. I'm not sure on the specifics but...it's also bad to get copper extra hot (hardening? B...

I can't speak for the current theories of best design trends, but...the battery compartment wouldn't have much airspace to flood, and the sub I was on maintained several large tanks with fresh water in them. Of course, any build-up of pressure would be vented to the outside...And also, I would have ...

Speak of the devil...I was a mechanic on a nuclear-powered submarine for a handful of years, back in 1977-81. We had a back-up diesel generator and a huge lead-acid battery, in case there was ever a problem with the reactor. I was told that if the torpedo room ever flooded with salt-water (just abov...

I highly value having a credit card (I have two), and I hate them both. Me and credit card banks are like porcupines mating, and I am the female. I occasionally have the need to be used in order to get something I want. For instance, when I was younger...I left a deposit-check with a car rental agen...

Thank you e-beach. That is a very good and useful link. On a side note, Harbor Freight Tools / HFT (yes...I know)...they have water-resistant Pelican case clones now under the Apache brand name. I hate when China clones something, but...Pelican cases are already made in China so...whatever. Apache b...

Thanks! There are several amp-output versions of the Headway cells ("HP" version shown above, 20C, 8Ah, 160A), the continuous 80A test for five minutes was the highest amp version. He dead-shorted the weakest cell at the end and got over 300A for a few seconds. The factory advertising claimed 160A c...

Awesome info, thanks! Charging and LVC methods I have a 100W 14V solar panel for emergencies, and 12V car battery chargers / alternators often actually put out a variable voltage around 14V. The 4S LiFePO4 at a fully-charged 3.65V would be 14.6V. LVC If I drain to only 3.0V per cell for long life (a...

I'm just starting this thread as a place to park useful info about 4S LiFePO4 as a 12V battery pack. Depending on the components the pack is powering, the charging system desired, and the LVC needed...using 18650 Li-NCA or Li-NCM can be too low at 3S or too high at 4S, however LiFePO4 has a lower no...

The larger the pack, the less of a difference there is in the battery-cell-per-volume between the common "rank and file arrangement, and a honeycomb layout. I prefer honeycomb because the is less air restriction and more air-flow allowed if they are packed-in to the same cell density as a common squ...